1. Field of the Invention
This invention relates to compressors for compressing gases such as coolant gas and the like, and more particularly to compressors having a mechanism for reducing pulsating of discharge pressure.
2. Prior Art
The compressors of a type in which a plurality of cylinder bores are formed in a cylinder block, and pistons are fitted to the cylinder bores, and the pistons are reciprocated with a predetermined phase difference by means of oblique plates and the like, are known as wobble type and swash plate type compressors and the like. In the compressors of this kind, the pulsating of the discharge pressure has heretofore been a problem. This pulsating causes vibration of the cooling apparatus through a piping, and becomes a cause of generation of abnormal sound. For this reason, inventions for reducing the pulsating of the discharge pressure have heretofore been proposed.
One of the inventions is disclosed in Japanese Patent Laid-Open Publication No. 58-98674. This invention has discharge holes formed in a valve plate in correspondence to each cylinder bore, and the resistance of the flow path is minimized according to the distance from the discharge holes to the discharge opening of the cylinder head, and the pulsating of the discharge pressure of each cylinder is equalized.
However, in the foregoing conventional example, distances from each discharge hole to a discharge opening are variable so that phases of the pulsating of the discharge pressure sometimes coincide and thus, the pulsating is amplified by the coincidence of the phases to generate large abnormal sounds.